Shock-absorbing tool handle

ABSTRACT

A shock-absorbing telescoping tool handle is disclosed having a larger diameter proximal portion and a smaller diameter distal portion. An internal spring in the handle portions is compressed when the handle portions telescope towards each other upon shock being applied to the tool handle. Guide mechanisms in the handle portion limit the extent of sliding motion between the handle portion and prevent relative motion of the handle portions. One or more wipers in the handle portion wipes away any snow, water or debris on the distal portion which could potentially enter the spring area. The spring may be located within the proximal portion or the distal portion of the tool handle.

RELATED APPLICATIONS

This is a continuation-in-part of U.S. application Ser. No. 08/727,024filed Oct. 8, 1996, now U.S. Pat. No. 5,816,634, which is acontinuation-in-part of U.S. application Ser. No. 08/640,986 filed Apr.19, 1996, now U.S. Pat. No. 5,690,374, in the names of Paul J. Jacobs,et al..

BACKGROUND OF THE INVENTION

This invention relates to shock-absorbing tool handles in general and,more specifically, to handles for shovels, spades, ice choppers, snowpushers and the like.

U.S. Pat. No. 4,691,954 to Shaud discloses a shock-absorbing tool handlefor a snow shovel. The Shaud handle has two parts or portions whichtelescope together and one part is joined to a detachable blade. Withinthe handle is a spring which compresses when the handle parts telescopetogether under axial load or shock imparted from the blade striking anobject hidden, for example, by the snow. The compression of the springreduces the shock impact to the user.

In the Shaud device, the handle parts are both tubular and the blade isattached to the distal part or portion in conventional fashion, theproximal portion being the end which is gripped by the user. Theproximal portion is narrower in diameter than the distal portion andslides into the larger distal tube. At the intersection of the twohandle portions, water, snow and other debris can flow downwardly intothe larger diameter distal tube and, if allowed to collect, adds weightto the shovel, it could freeze or otherwise trap debris within thehandle. With time, the spring could rust and other internal parts aswell. It is, accordingly, an object of this invention to provide ashock-absorbing tool handle which is not susceptible to the collectionof snow, water or other debris inside the handle.

SUMMARY OF THE INVENTION

The invention resides in a shock-absorbing tool handle comprising atubular proximal portion or proximal tube and a tubular distal portionor distal tube. The distal portion is formed or adapted to receive atool such as the blade of a snow shovel or a spade. The proximal portionis larger in cross-section than the distal portion and slides over thedistal portion in telescoping relationship. The handle portionstelescope axially toward each other when, for example, the blade orother tool meets resistance such as a ridge in a sidewalk being shoveledor a rock or any other hard object. An internal spring is locatedbetween the handle portions and is maintained between keepers locatedwithin the respective handle portions. Guide mechanism is located in thehandle portions to limit the amount of sliding motion and to permit thespring to be compressed between the keepers when axial shock is appliedto the blade. The guide mechanism also serves to prevent relativerotation of the handle portions.

There is at least one annular wiper in the proximal portion surroundingthe distal portion to prevent the entry of contaminants between thetelescoping portions in the area of the spring and to wipe contaminantsfrom the distal portion when the handle telescopes.

The wipers may take the form of an annular indentation in the proximalmember creating an inwardly extending annular bulge engagable with theouter diameter of the distal tube. The wipers also serve to add axialrigidity or integrity to the handle member.

The wipers may be annular or o-ring like members retained in an annularrecess in the proximal portion of the handle and made of low frictionplastic material slidable on the outer diameter of the distal tube orportion.

One of the spring keepers comprises a constriction in one of the handleportions supporting a washer and is illustrated as being located in thedistal portion. Another spring keeper comprises a washer abutting a pinextending transversely of one of the portions herein illustrated asbeing the proximal portion. The guide comprises aligned slots onopposite sides of the distal portion through which the pin extends.

An alternative form of spring keeper comprises a dowel firmly embeddedin the distal tube against which the spring abuts. Optionally, a washermay separate the dowel from the spring.

The tool, such as a snow blade, provided with an annular hub may besecured by screws passing through the distal tube into the dowel.

The above and other features of the invention including various andnovel details of construction and combination of parts will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims. It will be understood that the particularshock-absorbing tool handle embodying the invention is shown by way ofillustration only and not as a limitation of the invention. Theprinciples and features of this invention may be employed in varied andnumerous embodiments without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a snow shovel embodying the presentinvention.

FIG. 2 is a portion of the handle of FIG. 1 at the intersection of theproximal and distal portions.

FIG. 3 is a sectional view of the spring keeper taken along the lineIII--III on FIG. 2.

FIG. 4 is a sectional view taken along the line IV--IV on FIG. 2 withthe spring in the expanded condition.

FIG. 5 is a view similar to FIG. 4 with the spring in compressedposition.

FIG. 6 is a sectional view similar to FIGS. 4 and 5 disclosing a secondembodiment of the invention.

FIG. 7 is a sectional view similar to FIG. 4 disclosing anotherembodiment of the invention.

FIG. 8 is a sectional view similar to FIG. 4 disclosing still anotherembodiment of the invention, and

FIG. 9 is a tool handle for the shovel.

DETAILED DESCRIPTION OF THE INVENTION

The handle, generally designated 2, comprises a proximal portion 4 and adistal portion 6. The distal portion is adapted to receive a tool suchas a snow blade 8. The tool also may be a spade, ice chopper, pitchfork,snow pusher or any other equivalent tool. The handle may be of anylength. The blade may be attached by any convenient means such as a pin10. The proximal portion of the handle 4 is shown mounting an optionalhand grip 12. Both portions are tubular and the proximal portion 4 islarger in cross-section than the distal portion and slidable over thedistal portion in telescoping relationship. A spring 14 is containedwithin the handle portions and is compressible when the portionstelescope toward each other. It is illustrated as being in the distalportion. A first spring keeper, best seen in FIG. 4, generallydesignated 16 in the distal portion of the handle, comprises a washer 18which abuts an annular inwardly extending rib or constriction 20, formedby creating an annular indentation in the distal portion. A secondspring keeper, generally designated 22, comprises a washer 24 abutting apin 26 which passes through the proximal tubular portion 4 and isslidably received in diametrically opposed slots 28 formed in thetubular distal portion 6.

Before the spring 14 is compressed by axial force, that is, when it ismoved from the FIG. 4 to the FIG. 5 position, the pin normally residesat the top 30 of the slot 28 since the spring is under a small amount ofcompression when assembled. However, when the distal portion 6 of thehandle strikes a hard object or is otherwise compressed, it moves fromthe FIG. 4 to the FIG. 5 position by sliding into the proximal portionuntil the pin 26 abuts the bottom 32 of the slots 28

The slot 28 serves an additional function of preventing relativerotation between the proximal and distal portions of the handle. The pin26 is fixed in the proximal portion 4 and at all times is engagable withone or the other of the sidewalls of the slot limiting rotation to nomore than the clearance between the pin 26 and the slots 28.

Even though the proximal portion 4 of the handle is larger in diameterand telescopes over the distal portion 6 and helps to prevent the entryof snow, water and debris into the area of the opening, at least onewiper 40 is provided in the handle to affirmatively wipe away the snowS. Whereas only one wiper is necessary, two wipers are shown. Each wipercomprises an inwardly facing annular projection or bulge 40 formed byannularly indenting the proximal tube 4 at 36 and 38. The wipers haveessentially the same, but fractionally larger, diameter than the outerdiameter of the inner distal member 6. Upon compression, the wipers movedownwardly of the distal portion with the annular bulges 40 wiping snowS and debris from the distal portion 6 as seen in FIG. 5. The wipersalso prevent snow, debris and water from reaching the spring 14. Thewipers also serve the function of adding stability and axial integrityto the proximal and distal portions 4 and 6.

FIG. 6 shows an alternative form comprising annular O-ring like members44 retained and carried in annular, outwardly extending, retainingrecesses 46 in the proximal portion 4 of the handle. The O-rings may bemade of low friction plastic material such as Delrin™ or the like. Otherpossible materials for the wipers could be felt, for example, secured inthe proximal portion 4 and engagable with the distal portion 6 of thehandle to wipe snow, rain and debris from the exposed distal portion.

An alternative form of the first spring keeper will now be describedwith reference to FIG. 7. It will be noted that FIG. 7 is shown with thesnow blade 8 toward the top of the sheet whereas all other figures showthe handle oriented with the blade at the bottom of the sheet. A dowel50 made of wood or other equivalent material, such as a hard plastic, isforceably inserted into the end of the distal tube 6. When the face 52is flush with the end 54 of the distal tube 6, the internal face 56abuts the spring 14. Alternatively, a washer 60 may be employed betweenthe face 56 and the spring 14 to reduce wear on the dowel 50. The lengthof this dowel and the thickness of the washer 60, if one is used, areintentionally chosen to compress the spring slightly to prevent it fromrattling.

With the handle 2 in the FIG. 7 position, the spring 14 is dropped intothe distal portion 6 until it abuts the washer 24. If a second washer 60is chosen to be used, it is dropped into the tube and rests upon thespring 14. Thereafter, the dowel is forced into the tube by press orforce-fit and compresses the spring slightly. At least one fastener,shown as screw 62, passes through the hub 64 of the blade 8, the distaltube 6 and into the dowel 50. The screw or screws function to hold thedowel firmly in place and to hold the blade 8 onto the handle. By theuse of this construction, the constriction 20 in FIG. 4 is not necessaryand the assembly procedure is simplified slightly.

Another embodiment of this invention will now be described withreference to FIGS. 8 and 9. In essence, as will be seen in FIG. 8, thedowel 50 in the distal tube portion 6 is the same as in the FIG. 7embodiment, being secured therein by the screws 62 or other equivalentfastening members which hold the blade 8 in place. However, the spring14 in the FIG. 8 embodiment is located in the proximal or widercross-sectional portion 4 of the tool handle. The distal portion 6 ofthe tool handle has two ends, one represented by the reference character54 and the other by reference character 72. The spring may bear directlyagainst the circular end 70 of the distal portion 6 of the tool handle.Preferably, however, a washer 74 bears against the annular surface 70and the spring 14 bears against the washer. The other end of the springmay bear directly against the end 76 of a dowel 78 or a washer may beinterposed therebetween. The dowel 78 is held within the tubular portion4 by screws illustrated at 80 or by other equivalent fasteners such aspower driven nails.

A tool handle 12', best seen in FIG. 9, is secured to the end of thetubular portion 4 by a rivet 82 or other like fastener. The rivet 82 maybe used to hold, not only the tool handle 12' on the tubular portion,but to hold the dowel 78 inside the tool handle as well.

A benefit in this embodiment of the invention is in ease of assembly. Toassemble the spring 14, the tool handle may be held in a verticalposition with blade 8 downwardly. If desired, the washer 74 is droppedinto place against the annular surface 70, the spring 14 dropped intoplace and the dowel 78 pressed into the tool compressing the springslightly. Appropriate fasteners 80 and/or 82 hold the dowel 78 in place.

This embodiment is particularly useful in a tool handle of the typeknown as a "backsaver" where the handle itself is substantially in theform of a Z. In this instance, the proximal tube portion 4 would besomewhat larger than the distal tube portion 6.

We claim:
 1. A shock-absorbing tool handle comprising:a tubular proximalportion and a tubular distal portion, each portion having two ends; thedistal portion being adapted to receive a tool; the proximal portionbeing larger in cross-section than the distal portion and slidable overthe distal portion in telescoping relationship toward the tool; a springlocated within the handle, and compressible when the portions telescopetoward each other when force is applied in an axial direction; first andsecond spring keepers in the handle; the first spring keeper being oneend of the distal portion; the second spring keeper being a dowelforcibly received in the proximal portion; and guide mechanism in thehandle portions positioned to limit the sliding motion between theportions and to permit the spring to be compressed between the keeperswhen shock is applied to the handle.
 2. A tool handle according to claim1, wherein a washer is positioned between the said one end of the distalportion and the spring.
 3. A tool handle according to claim 1, whereinat least one fastener passes into the dowel through the proximal portionto secure the dowel therein.
 4. A tool handle according to claim 3,wherein at least one fastener passes into the dowel through the tubularproximal portion to secure a handle grip to thereto.
 5. Ashock-absorbing tool handle comprising:a tubular proximal portion and atubular distal portion, each portion leaving two ends; the distalportion being adapted to receive a tool; the proximal portion beinglarger in cross-section than the distal portion and slidable over thedistal portion in telescoping relationship toward the tool; a springlocated within the proximal portion of the handle, and compressible whenthe portions telescope toward each other when force is applied in anaxial direction; a first spring keeper in the proximal portion and asecond spring keeper engagable with the proximal portion; the firstspring keeper being one end of the distal portion; the second springkeeper being a dowel forcibly received in the proximal portion; and atleast one wiper in the handle surrounding the distal portion andengagable with the proximal portion to prevent the entry of contaminantsbetween the telescoping portions.
 6. A tool handle according to claim 5,wherein a washer is positioned between the said one end of the distalportion and the spring.
 7. A tool handle according to claim 5, whereinat least one fastener passes into the dowel through the proximal portionto secure the dowel therein.
 8. A tool according to claim 5 wherein atleast one fastener passes into the dowel through the tubular proximalportion to secure a handle grip thereto.
 9. A tool handle according toclaim 5, wherein the wiper is an annular projection in the proximalportion engagable with the distal portion.
 10. A tool handle accordingto claim 5, wherein the wiper is an O-ring of low friction plasticmaterial carried by the proximal portion and engagable with the distalportion.